I sympathise with you OP, I really do, my DH works away & my mother often comes for extended stays (at her behest) & I have had this exact charge levelled at me.
My children are lively, & yes, I know, many people on here see this as a synonym for badly behaved, but children are different, as are adults, some are lively & loud & exuberent some are more introvert, self contained and quite happy to entertain themselves.
I have seen (slightly smug) parents of two quiet, gentle & beautifully behaved DCs emerge shell-shocked & dishevelled after the arrival of a third, whirlwind personality.
For the main part, the general demeanor of children is luck, pure luck, no matter how many parents would like to believe differently.
It's how you deal with these differences that sorts the good from the bad parents.
In my case my children respond very well to firm, calm, consistent handling, any deviation & all hell generally breaks loose.
My mother personifies that deviation, she wasn't a great parent, lacked patience, was very shouty & made her displeasure know by withdrawal of affection.
She now employs the same tactic with my own children & they play her like a bloody violin. You can guarantee that left alone with them for more than 10 minutes it will result in a lot of schreechy shouting & children running wild. It generally takes them a good few days for them to calm down after she has visited, I now limit visits.
So yes, in her eyes they are demons, in mine, they are generally well behaved, lovely, personable little people that sometimes need a VERY FIRM LINE.
& my tactic with her?
IGNORE.